US2561514A - Strand brake - Google Patents

Description

July 24, 1951 l. D. HOUSEMAN STRAND BRAKE Filed April l2, 1949 INVENTOR. .ISAAC D. HOUSEMAN 5M ,a am,

` vented from falling.

Patented July 24, 1951 UNITED N STAT es PATENT oFFlcE t sTRANn BRAKE Isaac D. Houseman, Cleveland, Ohio Application April 12, 194e, serial No. 87,024

Y. 'Ifhis invention relates-to a safety attachment for a workman when employed on a scafoldingor other support operatively disposed at ,the side of a wall or building structure; where such supporting equipment is used it hasbeen the practice to provide a life .line for the workman .to

manually grasp in the event the scailold for any `,reason `drops or is displaced. However, it is vapparent that if an accident occurs Without warning', especially if the workman is beyond `thereach of the life line, he will be unable to grasp thelatter. The safety attachment herein disclosed provides a connection between the "workman and the life line, so that in the event of anaccident, such as (a) the scadold` orsup- "port, and/or its supporting means fall or break,

(b) the scaffoldor support is displaced (for eX- ample, due to the raising of some equipment), or (c) the workman loses balance and falls off the scaiiold the workman is automatically pre- MFor purposes of illustrating the preferred application of the invention, the workman is shown standing on a scaffold, which may be raised and lowered by suitable block and tackle, associated `with a life line attached to and depending from a high point of the wall or building structure and "relative 'to which the scaffold may b? adjusted Afrom time to time upwardly or downwardly to `change the working elevation, the safety attachment being detachably connected or clamped to the life line so as to be adjusted therealong when the scaiiold is moved to a different level in either direction.

vOne object of the invention is to provide an `improved safety attachment for a workman, having co-acting clamping elements for engaging `the life line, one of the elements being movable "andbiased by a spring, whereby the attach- `ment is adjustably connected to the life line,` fthe workman being connected to the movable `clamping element so that inthe event of an accident the weight of his body operates .through this element to eect a positive gripping of the life line by the clamping elements with` suiiicient l pressure or grip to prevent the workman from A falling.

In all safety attachments of the type referred to, of which I have knowledge, it has been the practice to adjustably clamp the attachment to the life line at an elevated position above the head of the workman, to permit the latter to freely move about the scaiolding Without danger of engagement with the attachment. However,

f When'lowering of the scaffolding becomes neces-l 1 Claim. (Cl. 188--65.2)`

j the structure l. Y j(preferably consisting of a rope) secured at its sary, release `of the attachment from the life line for adjustment to a lower position could not be made without iirst raising the scaiolding,

`whereby the workman could effect the release and lowering of the attachment to a new position; thusyn addition to the labor expended and time lost in raising and lowering the scaffolding the workman was forced to hold the movable clamping element in its inoperative position, and support the attachment while moving it downwardly to the lower position. Accordingly, an-

other object of the invention is to provide an improved safety attachment of simplied construction and provided with means adapted to be operated by a workman on the scaffold for adjusting the attachment to a lower position, without raising the scaffolding or supporting the attachment during adjustment thereof.

Another object of the invention is to provide an improved safety attachment embodying certain improvements in the form of construction shown in Letters Patent No. ../id', dated t January 11, 1949.

f line, parts being broken away.

Fig. 3 isan end elevation looking to the left Aof Fig. 2.

Fig. 4 is a top plan view.

1In the drawing, I indicates as an entirety a portion of a building structure. indicates as an entirety a scalold adjustably suspended by the usual block-and-tackle 3 in operative relation to 4 indicates a safety` or life line upper end to a high point of the structure or other elevated support and depending 'therefrom to a point adjacent or ybelow the lowest position. to which the scaffold may be lowered. The life line 4 is preferably disposed midway between the opposite ends of the scaffold 2 and may be related thereto on its inner or outer side.

The safety attachment consists 0i a belt 5 suitably bound around the workmans body, a clamp- `later .set forth.

vclamping .element I I.

3 ing mechanism indicated as an entirety at 6 and a flexible connection 1 (such as a rope or chain) of any desired length detachably connected at its opposite ends to the belt 5 and mechanism 6, as later set forth. The belt 5 may be provided with suitable straps adapted to extend over the workmans shoulders to hold the ,belt in place ;,in the event the scaffold drops or the workman falls off therefrom and is suspended by the life line, as later set forth, ther straps andbelt together; support the Workman in suspended position without undue binding or pressure effect on his body, as

would otherwise result if the belt 5 only were used.

`The clamping mechanism 6 consists ofV the. following; 8 indicates an elongated rigid member, preferably of U-shape in cross section,` soasto i In thisv arrangement, the U straddle the life line.

in any adjusted position thereof; that is, the frictional engagement of the clamping elements II and I2a with life line 4, under the influence of the spring I4, exceeds the tendency of the mechanism 6 due to its weight and that of the connecn tion 'I to gravitate. By swinging or rocking the' rocker I2 counter-clockwise, the clamping element I2a is disengaged from life line 4; when the life line 4 is disengaged in this manner, as 'later-set forth, the mechanism vmayibe bodily adjusted endwise of `the life line, such adjustment being effected as later set forth.

. .As shown, the outer end of the connection 1 Vis connected to the outer end of the rocker arm 12b, whereby the weight of the workman, in the event of anaccident as hereinbefore set forth,

mechanism 6 is guided endwise of "the-"lif'e line during adjustment thereof. The Sides of the member 8, at their upper and lower ends, are

extended laterally beyond theexposedside ofthe lifeline- 4 to provide pairs of spacedarms, IB, respectively. I I indicates a clamping element on the bottom wall of the member. Ii spacedrom-its ,upper end and adapted to engage the lifeline as The element II may consist-of -.a sectionof metal welded to the bottomwall Ea rof the member 8, asshown in the aforesaid Letters Patent, the exposed face ofthe ,metal seo- `tion, being concave and suitably knurled. toin- .sure .a gripping relation with the life line 4;. but v.by preference a portion ofthe-..bottom wa1118, .,endwise thereof, is embossed inwardly. substan- .tially1transversely, as shownat bato provide the I2. indicatesaI rocker of l.

substantially bell-crank. shape disposed between thearms Sand fulcrumed on-a removable pivot pin I3 extending through alinedopenings .formed in theouter end portions ofthe arms S. :The pin I3 is provided at one end with v.a headll3a bet -tween which and the adjacent arnr is provided 'a' coiled spring Iib `adapted tov bias thev pin I3 endwise (toward the left as viewed-in Fig. 3).

-'lheopposite end of the pin I3 is formed .with a *diametric-al slot I3rc in which an abutment 13o.,`

is pivotally` mounted Vintermediate its ends -joy ya pin yI 3d supported in the side walls of the slot |303. As shown in Figs. 3 and 4,*.When thev abutment I3c is disposed at right angles to the pin I3,-it engages the adjacent arm 9 tov lock the. pin I3 ,against endwise movement under theinfluence of the springV I3b, but when the abutment is .in-the tposition shown in dotted lines inF-igfS, the pin I3 may be projected through openings inthe arms .9 and'opening in the rocker I2 orrremovedfor a purpose later -set forth. =The outer-.end portion of the inner arm IZa ofthe rocker I 2 provides a clamping element to co-operate withthe clamping element I I to engage the life line between them. The outer faceof thearm IZa is substane- .f-tially concave in cross sectionand knurled to in- |'sure adequate frictional contact with the .life

.line 4. The vother arm I2b of the rocker I2-is connected toone .end of a springell. *,Thefoppo- `.site end ofthe spring is anchored-toene of .them arms I0. The spring. I4'serves'to rock the rocker I2 clo'ckwiseas viewed inli'ig.y 2, and-,thus effect engagement of the clampingy element I2a-with the life line' 4. As shown the arm I-Zb is relatively long as compared :to the arm I2a-to provide-,ade-f 'Aquate leverage in operation and the` spring .I,4is cfa size and strength -to maintain..thef'clamp ing element Iza against thelife `line Yand in ,0.13- position to the clamping-element II underpresexerts pull on the arm to insure a secure gripping The connection 'I is preferably detachably connected to the arm I2bt-by snap hook I5 and extends downwardly between the arms I0 andheld therewithin by Va pin I5 removably mountedlin alined openings formed in the 'outer `ends .thereof. The pinl I is preferably similarin construction to the pin I3, whereby it maybepositioned and removed in like manner." The arms IUand pin I6 serve to maintain theouter Vend portion of the connection 'I in position to, exert downward vpull on the arm I2b substantiallylin `its plane. To reduce wear and friction onitheconnection 1, a roller I"I is rotatablyY mounted. on thepinIG between the arms Iii. The flexible connection. 1 preferably consists of an outer section 1aand an inner section Ib the adjoining Vendsof which Vare detachably connected together by snaphooks I8, I 9, this arrangement serving to facilitate. the connection of the workman to the arm I2b and his disconnection therefrom. The. pins I3..and I6 are removable so that when initially hanging or. connecting the mechanism 6 on thelife line 4, the rocker I2, connection 'I and roller. I1 maybe disassembled to permit the life linetdbeposiv.tioned between thearms 9, ID (as shown), where- .uponthese parts may be reassembled, l.thereby .the life line 4. ln the form of linkage shown it .'consistsof main link 20a pivotally. mountedintermediate its ends on the outer face-of one side of the member 8 below the arms 9 and a separate link 2017 the innerendof which is pivotally .connected by means of a bolt ZI tothe outer endof .the link` 20a. The outer end of .the link :2017.V is

pivotally connected to the. outer end of abolt ZZeXtending laterally from thev arm I2b.v Asthe bolts 2|, 22 are removable, either one may be re- .moved to provide a `disassembly of thelinkage `from the. arm IZbwhen the mechanism is tobe ypositioned v.on thev life line or removed-,therefrom` vThe outer end of .thelinklc is provided with adependingpull-cord 23 the lowerendof which extends to a position Within the reacheof faworkman on the scaffold! and is v.provided-with Va :gripping device, such `as .a ring.'l 23a ,for the workman to catchliold of.

1^-Nihen the scaffold is to be raised to.a vhigher .working level, itis first raised.. to a-level therev above so .that the mechanism'` E .may be.4 repositioned vInfadjusting the mechanismmpwardly sure -to secure the mechanismr 6 .to -`the-life. 1ine 4. 1q5the workmancanfgraspthe link 20a onthepullr oord 23 to release the clamping elements Il, I2a, from the life line, and when the mechanism is in the desired position, the link or pull-cord (as the case may be) is disengaged, whereby the spring effects operation of the rocker I2 to secure the mechanism 6 to the life line.

Operation-When the mechanism 6 is initially connected to the life line, in its adjusted position, as above set forth, the workman may then don the belt 5 and attach the section 'lb to the belt 5 and section 'la to insure his safety. In. the event of an accident, such as herein referred to, it will be evident that the weight of the workmans body will exert a downward pull through the connecn tion 1, and the latter wiil rock the rocker clockwise and cause an increased gripping effect by the clamping elements Il, 12a, on the life line 4, and hence prevent the workman from falling beyond a level limited by length of the connection I from the position of the mechanism d.

When the scaffold i2 is to be` lowered to a lower working level, the adjustment of the mechanism 6 to a lower position. is effected by intermittent pulls on the pull-cord 23a the effect of which is to cause successive release and gripping movements of the clamping elements Il, 12a, with respect to the life line, the mechanism serving to gravitate during the periods when the clamping elements are released or disengaged from the life line, the intermittent pulls or operations of the pull-cord 23a being continued until the mechanism 6 is adjusted at the desired position.

To those skilled in the art t0 which my invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope thereof. My disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

What I claim is:

A safety means for a workman,` the combination with a scaffold adjustably suspended in relation to a wall for positioning at different working levels and a suspended life line disposed adjacent said scaffold, of a mechanism arranged to be adjustably clamped to said line above the scaffold in each adjusted position thereof, said mechanism consisting of an elongated member of U-shape in cross section enclosing said line,

the sides of said member at its upper and lower ends being extended laterally to provide alined pairs of arms, a portion of the bottom wall of said member, remote from its upper end, being transversely embossed inwardly to provide on its inner face a clamping element, a lever fulcrumed on and between said upper pair of arms, a clamping element on the inner arm of said lever in opposed relation to said first mentioned clamping element and arranged to co-operate therewith to engage and disengage said life line, a spring connected at its opposite ends to the outer arm of said lever and one of said lower arms and arranged to rock said lever in a direction to eifect engagement of said clamping elements with said life line under pressure, whereby said mechanism is adjustably iixed to and supported by the latter, a exible member connected at its outer end to the outer arm of said lever and extending therefrom through said lower pair of arms and adapted to be connected at its outer end to the workman, s0 that the weight of the Workman in falling serves to rock said lever and eifect a rigid clamping engagement of said clamping elements with said life line, whereby the workman is held in a suspended position on said life line, a main link pivotally mounted intermediate its end on one of the sides of said elongated member, a separate link pivotally connected at its inner end to the inner end of said main link and pivotally connected at its outer end to the outer arm of said lever, and a pull-cord depending from the outer end of said main link and terminating at its lower end within reach of a workman on the scaifold, pull on said pull-cord serving to operate said lever in opposition to said spring to disengage said j clamping elements from said life line to permit adjustment of said mechanism downwardly in relation to said scaifold.

ISAAC D. HOUSEMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 496,958 Scheid May 9, 1893 785,202 Dahlquist Mar. 21, 1905 1,194,062 Piche Aug. 8, 1916 2,205,933 Silvia June 25, `1940 2,458,943 Houseman Jan. 11,. 1949

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